Application and Practice of Rubbing Fastness Improver DM-2589N

The purpose of this paper is to introduce the application and Practice of a wet rubbing fastness improver DM-2589N in dark cotton fabrics. Methodology The influence of DM-2589N mass concentration, baking temperature and time on the rubbing fastness are studied. The effects of DM-2589N on different fabrics, different dyes, and the effects of DM-2589N and other finishing agents in the same bath are studied. Findings DM-2589N has excellent lifting effect on all kinds of cotton fabrics, and it is suitable for the improvement of rubbing fastness of fabrics dyed with reactive, direct, vulcanized and vat dyes. the optimum process is DM-2589N 40g/L, One dip and one rolling, baking temperature 150°C. Practical implications The dry and wet rubbing fastness of the finish products can be increased above Grade 3-4, which can meet the first-class quality requirements of customers. Originality/value – The wet-rubbing fastness improver DM-2589N can be used in the same bath with the fixing agent and softener without adjusting the pH value, which can simplify the production process, shorten production time and greatly improve production efficiency.


Introduction
The wet rubbing fastness of dyed textiles, especially deep colored cotton fabrics, usually cannot meet the requirements. Especially, the wet rubbing fastnesses of woolen fabrics and corduroy fabrics are lower than the wet rubbing fastness of cloth fabrics of the same color depth. This is mainly due to the fact that in addition to the color transfer in the testing process, the short velvet on the fabric will also be transferred to the friction head. So it is more difficult to improve the wet rubbing fastness of the pile fabric [1][2][3][4].
Rubbing fastness enhancers have been developed in China since the 1990s. After decades of development, progresses have been achieved. Although all of the main domestic auxiliaries manufacturers have products on the market, there is a lack of the all-round rubbing fastness enhancer, with remarkably improved wet rubbing fastness of cashmere fabrics, no selectivity in dyes, little effect on the feel of fabrics, and no need to adjust the pH value of working fluid in use. Some of the rubbing fastness enhancers on the market are only suitable for fabrics dyed by reactive dyes. And some are good for vulcanized, direct dyed fabrics, which need to be adjusted in use. The pH value of the working fluid may have the problem of increased color, while the handle of some finished fabrics is hard [5][6][7][8][9][10][11][12].
The rubbing fastness lifting agent DM-2589N is a special kind of high molecular polymer. It does not need to adjust the pH value of the working fluid in use. By fixing and crosslinking, the direct dyes can be significantly increased by forming films on the fabric. Reactive dyes, sulphide dyes and vat dyes can improve the wet rubbing fastness of fabrics and the wearability of dark textiles. The effects of reactive dyes, sulphide dyes and vat dyes on the wet rubbing fastness of fabrics are significant, and the effects on the color and the feel of fabrics are negligible.

Materials and Instruments
Cotton standard lining fabric (Shanghai Institute of Textile  Industry Supervision) (Shanghai Institute of Textile Industry)

Finishing Process of Rubbing Fastness Lifting Agent
The rubbing fastness lifting agent Xg/L, one dip and one rolling, has a rolling surplus rate of (80 ±5) and baking at 150°C for 120s.

Fabric Color Difference Value
According to CIE standard, the color difference of fabric was measured by Ultra Scan VIS spectrophotometer at D65/10 of light source, and the value of color difference of fabric was measured by using dyed fabric as reference.

Influence of DM-2589N Concentration
The 32s cotton knitted fabric with direct tanning resistance G dyed by active Tibetan green BF, was dipped into the rubbing fastness promotion agent DM-2589N 10, 20, 25, 30, 40, 50g/L, respectively. The color fastness and chromatic difference value E were tested in Table 1. It can be seen from Table 1 that the wet rubbing fastness of dyed cotton fabrics gradually improved When the mass concentration of DM-2589N increased from 0g/L to 30g/L, the color fastness to wet friction of dyed cotton fabrics gradually improved. When the mass concentration of DM-2589N increased from 30g/L to 50g/L, the color fastness to wet friction of dyed cotton fabrics did not increase. The wet rubbing fastness of DM-2589N with mass concentration of 30g/L reached the maximum of 4 grades. This indicates that the optimum mass concentration of DM-2589N is 30g/L.
According to the color difference in Table 1, the rubbing fastness improver DM-2589N has a significant effect on the wet rubbing fastness of cotton fabrics dyed with reactive dyes and direct dyes, and has little effect on the color and light of the fabrics.

Effect of Baking Temperature
32 S cotton knitted fabric with direct tanning resistance to black G dyeing with active Tibetan blue BF, impregnated with DM-2589N 30g/L, was baked at 130, 150, 160, 170°C for 120s, respectively. The color fastness to wet friction was tested in Table 2 after wetting.  Table 2 showed that when the baking temperature was raised from 130°C to 150°C, the lifting effect of DM-2589N on wet rubbing fastness of dyed fabrics became better. This was mainly because the increase of temperature that is beneficial to the fully film-forming of DM-2589N. When the baking temperature was 170°C, the lifting effect of wet rubbing fastness of fabric slightly decreased compared with that of 150°C and 160°C. In addition, extremely high baking temperature exerted serious damage to cotton fiber and largely affected the color and light of fabric. Therefore, the baking temperature after finishing with improver DM-2589N is determined to be 150°C.

Effect of Curing Time
32 S cotton knitted fabric with direct tanning resistance to black G dyeing with active Tibetan blue BF, impregnated with DM-2589N 30g/L, was roasted at 150°C for 60, 90, 120, 180s, respectively. The color fastness to wet friction was tested in Table 3 after wetting. Table 3 showed that when the curing time was extended to 90s, the rubbing color fastness was improved. And when the curing time was up to 120s, there was no improvement in wet rubbing color fastness, which indicated that the wet rubbing fastness lifting agent was fully crosslinked with the fiber at this time. Therefore, the baking time was 120s.

Lifting Effect of Different Fabric Rubbing Color Fastness
Several common pure cotton fabrics dyed with active Tibetan green BF, direct resistance to sun black G were impregnated with DM-2589N 30g/L, baked at 150°C for 120s. The color fastness to wet friction was tested in Table 4 after wetting.  Table 4 showed that DM-2589N can improve the wet rubbing color fastness of common cotton fabrics (including pile fabrics) to 3-4 or above. It manifested that DM-2589N can improve wet rubbing fastness of all kinds of cotton fabrics.

Enhancement Effect of Rubbing Fastness of Fabrics Dyed with Different Reactive Dyes
Active turquoise blue (BES), active Tibetan blue (BF), active black (RG), super red RW stained 32 S cotton knitted fabrics, baked at 150°C for 120s at 30g/L DM-2589N, were tested for wet friction color fastness and color difference E in Table 5 after wetting.  Table 5 showed that DM 2589N, a lifting agent for rubbing fastness, can improve the wet rubbing fastness of dyed fabrics with different reactive dyes. But all of them can reach 4 grades, which meet the requirement of wearing. This indicated that DM-2589N was used in the finishing of dark fabrics and had no selectivity for reactive dyes.

Effect of Direct, Vulcanized, Vat Dyestuff Dyeing
32 S cotton knitted fabrics dyed with direct dyes, sulfur dyes and vat dyes respectively, finished with DM-2589N 30g/L, were tested for color fastness to wet rubbing E as shown in Table 6.  Table 6 showed that DM-2589N dyestuff, vulcanized dye and vat dyestuff can improve the dry and wet rubbing fastness significantly; wet rubbing fastness was 3 -4, dry rubbing fastness was 4-5, and the finishing had little effect on the color and light of the fabric.

Color Fastness to Friction of Softener and DM 2589N in the Same Bath
On 32 S cotton knitted fabric dyed with active BF, super red RW, the softener 20g/L DM-2589N 30g/L was treated in the same bath. The color fastness to wet friction was tested in Table 7.  Table 7 showed that the effects of different softeners on the DM-2589N rubbing fastness were different, indicating that DM-2589N had a certain selectivity to softener, in which silicone oil 0127 and DM-2589N in the same bath had no effect on dry and wet rubbing fastness. Dry and wet rubbing color fastness can be raised to level 4, while achieving soft and smooth feel.

Effect of Active Fixing Agent, Softener and DM-2589N on the Improvement of Friction Color Fastness in the Same Bath
On 32 S cotton knitted fabric dyed with active BF, super red RW, fixing agent DM-2517 10g/L, silicone oil 0127g/L, DM-2589N 30g/L in the same bath, the color fastness of each color fastness was reported in Table 8 and 9.  Table 8 / 9 showed that the rubbing fastness lifting agent DM 2589N was treated in the same bath with the fixing agent DM 2517 and the silicone oil 0127. The three processes of hand feeling finishing, fixing and wet rubbing finishing are combined into one process. After finishing, the fastness to rubbing, soaping and perspiration can reach grade 4 or above, It simplifies the production process of dyeing plant and helps to improve production efficiency.

Production Practice of Dyeing Factory
The technical indexes of DM-2589N met the requirements of production, and then the samples were produced in 2 printing and dyeing factories in Guangdong area. Production and use of equipment: Hong Kong CHTC Fong's Industries Company Limited Men Fushi molding machine.

Production Engineering
The machine was impregnated and rolled and baked at 150°C. The speed of the machine was between 15 to 20 m/min.

Results of Mass Production
Observe the cloth effect of the above four kinds of fabrics and test the color fastness and the color difference value of the friction. The recorded results were reported in Table 11.

Large Production Result Analysis
The large production practice showed that the rubbing fastness lifting agent DM-2589N significantly improved the friction color fastness of dyed fabrics. Meanwhile, the production continuity was good, the reproducibility was good, and the finishing had little influence on the color and light. The same bath finishing with silicon oil 0127 not only improved the quality of the processed cloth seed, but also simplified the production process and the comprehensive economic benefit.

Conclusion
The main results were as follows: (1) DM-2589N was used in the finishing of dark fabrics. It had no selectivity for dyes, and can improve the wet rubbing fastness of reactive dyes, direct dyes, sulphide dyes and vat dyes to 3 or higher grade. DM-2589N was used in the finishing of various dark cotton fabrics such as yarn card, poplin, plain fabric, bead cloth, abrasive cloth, sanitary cloth and pile fabric. It had excellent effect on improving the wet rubbing color fastness of fabric, and had little influence on the color and feel of fabric.
(2) DM-2589N had no phosphorus, formaldehyde, heavy metal, organohalide and REACH regulations. The pH value of the working solution was not adjusted when it was put into use. It combines hand feeling, fixing and wet rubbing with fixing agent DM-2517 and silicone oil 0127 in the same bath finishing process. After the same bath finishing, the color fastness of the fabric to friction, soaping and perspiration can reach grade 4 or more, which not only improves the wearing performance of the dark fabric, but also simplifies the production process of the dyeing plant, and has good economic and social benefits.